(i) Field of the Invention
The present invention relates to, for example, an air cell unit and cushion which is having a plurality of air cells disposed in some flat direction on a bed of a hospital or on a wheelchair and which is used for preventing occurrence of a bedsore on a patient.
(ii) Description of the Related Art
A generally known cushion comprises a plurality of air cells disposed in some flat direction and being capable of housing air respectively, and a ventilation passage for connecting the interiors of the air cells each other and equalizing the air pressures in the air cells. Said cushion disperses the pressure being exerted on the body on the air cells and prevents occurrence of a bedsore.
By the way, above mentioned cushion with air cells is composed of a upper sheet-like member formed integrally with a plurality of air cells and a bottom sheet-like member having area equivalent to the upper sheet-like member. The upper sheet-like member has the area according to the size of the bed and is made from flexible material such as rubber material or resin material. The bottom sheet-like member is pasted to the undersurface of the upper sheet-like member, and the opening portion of each air cell bottom is closed by the bottom sheet-like member. Also, the ventilation passage for making the insides of the air cells communicate each other is disposed between those sheet-like members.
In this case, it is desirable to respectively set up the size and the arrangement of the air cells according to the patient's height, body shape, or the state and condition of the affected part in order to disperse more effectively the pressure being added to the body.
However, in the above-mentioned cushion, it is necessary to change the shape of a upper sheet-like member in order to change the size and arrangement of air cells. Also, since the air cells of the upper sheet-like member are molded by a plurality of concave portions or convex portions of the metallic mold, a plurality of metallic molds are needed according to the number of the kind of upper sheet-like member. Namely, it is impossible to change the size and arrangement of the air cells according to the patient's height, body shape, or the state and condition of the affected part.
Also, in order to disperse the pressure added to the body, it is desirable that air cells are flexible. However, the flexible air cell tends to generate an air leak by breakage. Also, since air cells communicate with each other by a ventilation passage, other non-breakage air cells are influenced by breakage of some air cells. Therefore, when the air cell is damaged, it is necessary to perform repair of a breakage part, or exchange the cushion itself. By this, in repair of a breakage part, time and effort is taken, and when it is the exchange of the cushion itself, expense costs dearly.
Moreover, in order to keep air cells always clean, it is desirable to use respectively a new cushion for every patient in a hospital. However, since much expense is needed to purchase cushions for every patient respectively, under the present circumstances, the cushion is washed and used repeatedly. In this case, the air cells are flexible and breakable, and it is difficult to wash a plurality of air cells being disposed each other. By this, it is impossible to wash the air cells fully.